I call BS on that. Both HE-400, and especially the LCD2, are very tight in their bass, but they extend down low and still provide deep, deep bass when called for.
I don't know what 'rumble' means, so I won't try to discuss that.
My initial question was how does the HE-6's low bass presence compare to HE-400 or LCD2. Can you answer that?
Yes I supposw.
The presence is similar but it hits slightly less deep.
You can ask preproman aboit that... He has all 3.